function getBase64Image(img) {  
            var canvas = document.createElement("canvas");  
            canvas.width = img.width;  
            canvas.height = img.height;  
            var ctx = canvas.getContext("2d");  
            ctx.drawImage(img, 0, 0, img.width, img.height);  
            var ext = img.src.substring(img.src.lastIndexOf(".")+1).toLowerCase();  
            var dataURL = canvas.toDataURL("image/"+ext);  
            return dataURL;  
       }